The location of a mobile, wireless or wired device is a useful and sometimes necessary part of many services. A Location Information Server (“LIS”) may be responsible for providing location information to such devices with an access network. The LIS may utilize knowledge of the access network and its physical topology to generate and serve location information to devices.
The LIS, in general terms, is a network node originally defined in the National Emergency Number Association (“NENA”) i2 network architecture addressing a solution for providing E-911 service for users of Voice over Internet Protocol (“VoIP”) telephony. In VoIP networks, the LIS is the node that determines the location of the VoIP terminal. Beyond the NENA architecture and VoIP, the LIS is a service provided by an access network provider to supply location information to users of the network by utilizing knowledge of network topology and employing a range of location determination techniques to locate devices attached to the network. The precise methods used to determine location are generally dependent on the type of access network and the information that can be obtained from the device. For example, in a wired network, such as Ethernet or DSL, a wiremap method is commonplace. In wiremap location determination, the location of a device may be determined by finding which cables are used to send packets to the device. This involves tracing data through aggregation points in the network (e.g., Ethernet switches, DSL access nodes) and finding the port for which packets are sent to the device. This information is combined with data available to the LIS (generally extracted from a database) to determine a final location of the device.
In wireless networks, a range of technologies may be applied for location determination, the most basic of which uses the location of the radio transmitter as an approximation. The Internet Engineering Task Force (“IETF”) and other standards forums have defined various architectures and protocols for acquiring location information from an LIS. In such networks, an LIS may be automatically discovered and location information retrieved using network specific protocols. Location information may be retrieved directly or the LIS may generate temporary uniform resource identifiers (“URI”) utilized to provide location indirectly (i.e., location URI). Geodetic and civic positions of a mobile device may be determined as a function of location information from the LIS. There is, however, a need in the art to overcome the limitations of the prior art and provide a novel system and method for providing location services for multiple access networks from a single location server.
One embodiment of the present subject matter provides a method for determining the location of a target device attached to an access network connected to a location server, the location server having a plurality of access networks connected thereto. The method may comprise receiving a location request for a target device, identifying the target device as a function of one or more parameters, and identifying an access network from the plurality of access networks to which the target device is attached as a function of the one or more parameters. Each access network in the plurality of access networks connected to the location server may be assigned one or more logical identifiers by which an individual location request may be allocated to the respective access network. An estimated location of the target device may then be determined as a function of the one or more logical identifiers using a location algorithm appropriate for the identified access network.
Another embodiment of the present subject matter provides a method for locating a target device attached to an access network in a system having a plurality of distinct access networks connected thereto. The method includes receiving a location request for the target device and serving the plurality of distinct access networks using a single location server without regard to underlying protocols employed by the access networks and target device.
A further embodiment of the present subject matter provides a system having a location server with a plurality of location generators for receiving location requests for target devices and for determining a location of the target devices, the location requests having one or more parameters and being classified into location groups having as a function of at least one common parameter. The location server may also include a plurality of location determination functions for each location generator. The system may include a plurality of access networks connected to the location server, each access network being associated with a location generator as a function of a range of logical identifiers by which a location request may be allocated to the respective access network, wherein the location groups restrict a range of target devices locatable by a location request as a function of said one or more parameters, and wherein each location determination function corresponds to a location algorithm appropriate for a respective access network.
These embodiments and many other objects and advantages thereof will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of the embodiments.